The electric field manipulation of magnetization [1,2] became a subject of acute interest, since it provides a low energy consumption and sub-nanosecond switching time. The yield of such process depends on the anisotropy energy variation in response to the applied electric field and therefore a wide variety of studies have been dedicated to this topic. In this work we present a combined experimental-theoretical study of the perpendicular magnetic anisotropy (PMA) electric field modulation in magnetron-sputtered epitaxial Pt(111)/Co/MgO type systems. Ab-initio calculations of voltage-controlled PMA have been performed using the Full Potential Linear Augmented Plane Wave FP-LAPW code Wien2k [3]. A supercell model has been used to describe the multilayer configuration and the electric field has been applied using a zig-zag additional potential in the Hamiltonian. The anatomy of PMA and its electric field dependence has been theoretically analyzed within the framework of two main mechanisms: the surface charge doping which alters the relative occupation of electronic orbitals at the interface and the intrinsic interfacial dipole field. The main issue of our calculation is the prediction that the adjunction of Pt at top Co/MgO interface in Pt/Co/MgO ultrathin structures enhances the perpendicular anisotropy by about 84% and its electric field variation rate (Fig.1 (a), (b)). These theoretical predictions have been further used to design, grow by sputtering samples and pattern spintronic devices dedicated for the experimental analysis of the voltage response of magnetic anisotropy. As expected, in both standard Pt/Co(1nm)/MgO and top interface tailored Pt/Co(1nm)/Pt/MgO samples, the room-temperature magnetometry experiments demonstrated the out-of-plane remanent magnetization configuration related to surface PMA. The electric field influence on the PMA has been then studied on Hall-bridge patterned samples with a top-gating insulator (Fig.2 (a)), suitable for Anomalous Hall Effect magnetometry. In these devices, a qualitative agreement between the theoretical predictions and experimental results has been observed. The asymmetric variation of the anisotropy energy dependent on the polarity of the electric field, which was deduced from the ab-initio calculations is also reflected in the asymmetric variation of the coercive field as a response to the applied voltage (Fig.2 (b)). Supplementary insight into the anatomy of the mechanisms involved in the electric field effect on the coercive field, driven by the electric field modulation of the surface anisotropy, is further provided within a macrospin approach.

**References:**

References: [1] W-G. Wang et al, Nature Mater., vol. 11, pp. 64-68, 2012. [2] Y. Shiota et al, Nature Mater., vol. 11, pp. 39-43, 2012. [3] P. Blaha et al, J. Chem. Phys., vol. 152, p. 074101, 2020.

**Images:**

![](https://assets.underline.io/uploads/markdown_image/1/image/8aa1914679751d7ed802354b310f9987.jpg)
Fig.1 Ab-initio calculation of electric field variation of the surface perpendicular anisotropy Ks for Pt/Co/MgO (a) and Pt/Co/Pt(1ML)/MgO (b) supercells

![](https://assets.underline.io/uploads/markdown_image/1/image/6a2fc3c369a03e3f0c26127a23d3fb4c.jpg)
Fig.2 (a) Hall-bridge UV lithographically patterned devices; (b) Variation of coercive field, surface anisotropy with the applied electric field.

 Electric field modulation of interfacial magnetic anisotropy in magnetron-sputtered Pt/Co/MgO ultra-thin structure with chemically tailored top Co interface

*Session Chair: Hélène Béa, CEA-SPINTEC*

These on-demand presentations are available to view at your leisure. 

IQ: Electric Field Effects and Magnetoresistance

poster

INTERMAG 2021 Welcome Video



	
<figure class="video_container">
 <iframe src="https://screencast-o-matic.com/player/crflqFVnUpZ?v=6&ff=1&title=0&controls=1" width=640 height=360 frameborder="0" allowfullscreen="true"> </iframe>
</figure>

Want to buy a ticket? 

Register for INTERMAG 2021 here

[![](https://assets.underline.io/uploads/markdown_image/1/image/17ce76e7960db633258024eef8d6da7f.png)](https://intermag.org/register)

Got your ticket, but still can’t access the event?

Contact us and our team will look into it.

Roxana-Alina One

1

SHORT BIO

Presentations

Electric field modulation of interfacial magnetic anisotropy in magnetron-sputtered Pt/Co/MgO ultra-thin structure with chemically tailored top Co interface

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES